The Influence of Silicon Dioxide on the Stability of the Phase Composition and Mechanical Properties of Alumina-Toughened Zirconia-Based Ceramics

Determination of the ATZ ceramics with different SiO-=SUB=-2-=/SUB=- contents tensile strength by the "brazilian test" method

“…2). The observed embrittlement of CaO−ATZ + SiO 2 ceramics at C SiO 2 > 5 mol.% is fully consistent with the obtained data during deformation of similar ceramics by uniaxial compression and three-point bending [14], as well as during diagnostics of fracture viscosity [10].…”

“…According to the previous data, CaO−ATZ + SiO 2 -ceramics with 5% content of silicon dioxide has an increased compression strength (σ c = 2.4 GPa [13]) and a high correlation of hardness and fracture viscosity (H = 10.9 GPa, K C = 12.43 MPa • m 1/2 [10]). The detected increase of ATZ-ceramics strength upon injection of SiO 2 additive is explained in terms of an increase of mechanically induced transformability of the tetragonal phase of zirconium dioxide and, respectively, enhancement of the role of the transformational strengthening mechanism.…”

“…The samples of zirconium ceramics (stabilized with calcium oxide), reinforced with aluminum oxide having a different content of silicon dioxide (CaO−ATZ + SiO 2 ) were made using ZrO 2 (Sigma-Aldrich), Al 2 O 3 (Hongwu), CaO (Reachem) and SiO 2 powders (Sigma-Aldrich). The correlation of the initial (before grinding) molar concentrations of ZrO 2 : CaO : Al 2 O 3 was maintained constant -88 : 6.2 : 5.8 in compliance with [10] SiO 2 in relation to the obtained mixture was varied from 0 to 6 mol.%. Dispersion of the prepared powder mixtures in distilled water, grinding in the Pulverisette planetary mill (Fritsch), mixture drying, sample forming in the shape of cylinders with the diameter of 10 and thickness of 2 mm, as well as their sintering were performed in full compliance with the conditions outlined in [10].…”

“…The correlation of the initial (before grinding) molar concentrations of ZrO 2 : CaO : Al 2 O 3 was maintained constant -88 : 6.2 : 5.8 in compliance with [10] SiO 2 in relation to the obtained mixture was varied from 0 to 6 mol.%. Dispersion of the prepared powder mixtures in distilled water, grinding in the Pulverisette planetary mill (Fritsch), mixture drying, sample forming in the shape of cylinders with the diameter of 10 and thickness of 2 mm, as well as their sintering were performed in full compliance with the conditions outlined in [10].…”

“…Variation of composition (stabilizer type, correlation of concentration of ATZ-ceramics components) and the microstructure design (size of crystallites t-ZrO 2 and reinforcing elements) allows for controlling the correlation of hardness values H and fracture viscosity K C (on H = 18 GPa and K C = 2.7 MPa • m 1/2 [8] up to H = 10.4 GPa and K C = 16 MPa • m 1/2 [9]). Injection of additional components (e.g., SiO 2 or SrAl 12 O 19 ) makes it possible to attain not only an improved correlation of the values of H and K C [10], but also a manifestation of plasticity features of zirconium dioxide-based composite ceramics at room temperatures [11][12][13][14].…”